A conventional power supply of a transformer inputs, converts, and outputs a voltages via a transforming circuit to start a light string. The light string requires direct currents and outputs alternating currents, so the power supply is fixed between the light string and a main supply.
CN 203911035 discloses a power supply of a transformer contains a plug and a lid, wherein the plug has an input interface, and the lid has a DC output interface. The input interface is connected with the alternating currents, and the alternating currents are transformed into direct currents by a voltage transforming unit in the plug, thereafter the direct currents are supplied to the light string via the DC output interface.
However, the power supply cannot connect with plural bulbs of the light string simultaneously.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages.